In the past, TN-mode liquid crystal displays (LCDs) were used often. Recently, however, VA-mode LCDs and IPS-mode LCDs with better viewing angle characteristics than the TN-mode LCDs have been used more and more extensively. Meanwhile, MVA-mode LCDs and S-IPS mode LCDs with further improved viewing angle characteristics have been used for TVs and monitors lately.
The VA mode realizes black display of higher quality than the IPS mode, and therefore, contributes to presenting images at a higher contrast ratio. But the VA mode is inferior to the IPS mode in that the r characteristic has heavier viewing angle dependence.
To overcome this problem, Patent Document No. 1 proposes a method of averaging the viewing angle dependence of the γ characteristic by splitting each pixel into a plurality of subpixels and applying mutually different voltages to those subpixels. The LCD disclosed in Patent Document No. 1 has a configuration in which display signal voltages are applied independently of each other to a plurality of subpixels that a single pixel has. That is to say, if each pixel is made up of two subpixels (which will be referred to herein as “first and second subpixels”, respectively), a source bus line for applying a display signal voltage to the first subpixel and another source bus line for applying a display signal voltage to the second subpixel need to be provided separately. That is why if each pixel is divided into two, then the number of source bus lines and the number of source drivers need to be doubled. Also, two different display signal voltages are set in advance and stored in a lookup table so to be applied to the first and second subpixels, respectively.
On the other hand, Patent Document Nos. 2 and 3 disclose LCDs, each including a plurality of subpixels that will have mutually different luminances responsive to at least one display signal voltage applied. In such an LCD, since a common display signal voltage is applied through the same source bus line to the first and second subpixels, there is no need to increase the number of source bus lines or source drivers according to the number of divisions.                Patent Document No. 1: Japanese Patent Application Laid-Open Publication No. 2003-295160        Patent Document No. 2: Japanese Patent Application Laid-Open Publication No. 2004-62146        Patent Document No. 3: Japanese Patent Application Laid-Open Publication No. 2004-78157        Patent Document No. 4: Japanese Patent Application Laid-Open Publication No. 6-332009        